I think negative behaves the same as reversal with tungsten light and daylight except the difference isn't that noticeable since negative is very forgiving. For example the sensitivity of Efke emulsions was for tungsten light, and not daylight : you had to underexpose by one stop in daylight. I didn't know it at the time when I used some but I have great prints from it. The negatives are bullet proof though, especially in scenes under bright sun...
Thanks for clearing that one up. I was confused.
Originally Posted by Tofek
Thanks - I'm clear on the film rating issue now.
Originally Posted by johnielvis
Yes, a lab processed Tri-X might be good idea as a benchmark.
I've got 4 carts of Tri-X in the fridge - so i'm not really saying goodbye, Tri-X, so much as 'Au revoir Tri-X and bon matin, Pan-X'.
The change might shed some new light on my processing. ;)
I don't think that the loss of speed due to fog being developed in the 1st dev. If fog had been created in the 1st dev, it would have been bleached away thus resulting in a brighter image. It's the opposite.
It is rather that all the negative silver isn't developed and thus isn't bleached. There are some silver halides left in the transparent parts because they haven't been developed as negative. The fog is created in the 2nd dev, because too much silver is left in these transparent parts. That's why a silver halide solvent would help to gain speed.
So I went back on my word. I just finished the 16 minute test before I do the Pan-X. Just to call it a wrap.
Tri-X Reversal. D19 1+0 , 16 minutes 1st / 8 minutes 2nd.
Here's the news. Nothing to be gained between 12 and 16 minutes. 100 ASA is still the best result but probably not as good as 12. More contrast and tones crunched.
But then there was only little improvement/difference to the 100ASA exposure between 8 mins and 12 mins so I was kind of expecting it.
200ASA more usable but the bottom 3 zones are more or less combined flat black.
I'll post the scans next week.
I think I might try johnielvis' suggestion of the weaker solution when I get the time. I reckon take the 8min version as a plateau and run it diluted at 1+1 for 16m.
In the meantime Pan-X tests have started and are moving into the silver solvent stage next. I feel happier having two emulsions under test as one is more likely to yield results and that will take me into production sooner.
in agreement with your comment - after my Pan-X test - I too was beginning to think that D19 is just not active enough. I've got a good image starting (after using hypo to clear the base silver) but only at 50ASA with 12mins of development. The 100 ASA exposure is unusable.
(With regards your 10 minutes rule - I absolutely could not get noticeable fogging with Tri-X. Pan-X is another story.)
I was loath to start using higher temperatures but I might give it a shot.
Working out the right relationship between developer strength/time and hypo qty does look slightly like trial and error. But I got nothing useable in Pax-X until I added it.
Even though it did not seem to suit Tri-X specifically, I'm not sure why you say hypo should be avoided though, as even Kodak put it in their d94a. It's also what what i can see in every reversal recipe in the literature.